Update MarkupSafe pin for compatibility

[alecpm]

See PR #243

Currently sphinx-js pins the markupsafe to the exact version 2.0.1. This can result in issues isntalling packages that depend on sphinx-js but also have dependencies that require newer versions of markupsafe (for example werkzeug 3.0.x).

Updating the pin to allow for versions >=2.0.1 resolves this issue and does not appear to present obvious compatibility problems. The single version pin significantly limits the ability to use this tool in projects, and is inconsistent with the other version specifications in setup.py.